The present invention relates to an analog timepiece having two forward and reverse time correction functions utilizing a high speed stepping motor.
Quartz timepieces that have analog displays include a crystal controlled oscillator and a stepping motor display driver. In order to provide for time correction, a correction control member such as a crown had to be positioned and rotated to produce movement of the hands of the timepiece in response to impulses provided by the stepping motor.
In U.S. Pat. No. 4,192,134 issued to Yoshida, an electronic analog timepiece was disclosed in which a forward and reverse time correction operation is performed with the use of a single correction switch. The switch could also provide for rapid time correction within a short time period. A push button is used for time correction switching.
U.S. Pat. No. 4,112,671 issued to Kato et al. discloses fast time correction to prevent the standard time from gaining during time correction.
Generally, timekeeping signals actuate drive circuits to provide drive pulses of selected wave shapes to drive a stepping motor which turns hour, minute and sometimes second hands. The drive pulses may be repetitive wave shapes of the same polarity for driving stepping motors as disclosed in U.S. Pat. No. 3,818,690 issued to Schwarzschild and U.S. Pat. No. 4,070,279 issued to Oudet et al. which are incorporated herein by reference. Alternately, the stepping motor may be of the type receiving pulses of alternating polarity as described in the patent issued to Kato et al. described above.
Movement of the hands can be acclerated during time correction and driven at various speeds in both the forward and reverse directions. Examples of this type of time correction function are disclosed in U.S. Pat. No. 4,173,863 issued to Motoki and U.S. Pat. No. 4,030,283 issued to Sauthier.
It is also known to use a single push button switch for controlling various time setting modes for a digital watch as illustrated in U.S. Pat. No. 3,953,964 issued to Suppa. U.S. Pat. No. 4,192,134 issued to Yoshida shows a single push button that achieves alternating forward and backward hand movement for time correction. One time correction problem associated with quartz analog stepping motor watches is that the watch timekeeping is disturbed if time zone changes are made during which the hour hand is repositioned. In the Motoki patent, previously discussed, one hour time correction may be performed but the watch must be reset by advancing the hands at a slower rate once the hour hand moves ahead or moves back by one hour.
Additional patents involving time correction means include U.K. patent application No. 2,070,816 A issued to Mouthon et al., U.S. Pat. No. 4,199,932 issued to Berney, U.S. Pat. No. 4,092,822 issued to Droz et al., U.K. patent application No. 2,032,145 A issued to Jaunin, U.S. Pat. No. 3,928,959 issued to Naito, U.S. Pat. No. 4,196,578 issued to Besson, U.S. Pat. No. 4,143,509 issued to Weibel, and U.S. Pat. No. 4,275,463 issued to Ishida.
Accordingly, it is an object of the invention to produce high speed time correction of the minute, hour and second hands using a high speed stepping motor.
It is an object of the invention to provide for a deceleration from fast time correction within a predetermined time prior to the end of either of two time correction functions.
Another object of the invention is to automatically provide for an adjustment of time correction as the stepping motor decelerates by the amount of time required for correction to occur so that the actual timekeeping of the watch is not disturbed.
An additional object is to provide two circuits one for time zone and the other for time setting correction functions where each circuit produces time correction in both the forward and reverse directions.